# Creating multiple constant current channels

Hi,

I might not have selected the correct category.

So, I have started working with ni USB 6009. I have a constant current source and want to get multiple constant current channels on a breadboard using the ni from this current source. Could anyone please tell me how to set the connections. Something very simple would be helpful. Thanks in advance!

Welcome to the forum.

From what little I’ve read this morning, it looks like the NI USB 6009 is a fairly standard data aquisition device. It has analog voltage I/O, digital I/O and a digital counter.

What are you wanting to measure, and what are you going to drive with the constant current source?

It will probably get good answers faster if you briefly describe what you are trying to do at a high level. (example: I want to read five 4 to 20mA whirligig sensors, model number xx-zz)

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Hi, Thank you for getting back. So, we want to test a logic operations for our samples. Our samples are structured thin films on silicon substrates. Now we have made 8 diametrically opposite pairs of contacts on the long edge of the rectangular samples and on the short edge we have one contact each for voltage probes. And we want to test what this voltage drop is when any combination of currents are applied on the sample. By combination of currents I mean, let’s say we choose +200 uA as the high, so for one particular measurement we choose to apply this current for 5 out of 8 current channels, and 0 current for the others, on the sample and so on for all 256 (2^8) combinations of currents. Pardon my explanation, I have hardly worked with electronics before. Please let me know if you have suggestions and if you need more clarifications.
Thank you,

Assuming you have already verified that the accuracy and measuring range of the NI USB 6009’s analog inputs is correct for this application, this seems pretty straightforward.

1. Connect the eight analog inputs to the eight voltage reading points
2. Make your first constant current power on/off selections
3. Read/record the eight voltages
4. Change to the next set of constant current power on/off selections
5. Goto 3
repeat for all 256 variations

If you want to automate the current selection/measurement cycle. That is a much bigger project where hundreds of man hours will get burned designing, building, coding, and testing the custom test system.